EU law has a complex relationship with the concept of peremptory norms. On the one hand, the case law of the ECJ shows a pattern of ‘avoidance’ of peremptory norms of general international law, namely a reluctance by this Court to consider the legal effects of such norms in cases where they may be relevant. This is clear in the Kadi and Front Polisario/Western Sahara sagas. On the other hand, EU law has ‘assimilated’ the concept of peremptory norms more than it may seem at first sight. Indeed, it may be affirmed that EU law has its own system of peremptory norms. Such as system is based on norms and principles that have some of the defining features of the peremptory norms of general international law (including a system of enhanced responsibility for serious breaches of such peremptory norms). While, in analytical terms, this characterization does not matter much for EU law, it is certainly critical to the proposition that general international law does not exclude the existence of a regional jus cogens.